Electric switch



lJune l2, 1928.

J. D. HILLIARD ELECTRIC SWITCH Filed Feb. lO, 1923 John D.Hlla1^d) b9WML His Abbou*` ai T169.

Patented J une 12, T928.

UNITED STATES i PATENT OFFICE.

JOHN D. HILLIABD, OF SCHEN'EOTADY, NEW YORK, ASSIGNOR TO GENERALELECTRIC COHPAN Y, A CORPORATION OF NEW YORK.

ELECTRIC SWITCH.

Application led February 10, 1923. Serial No. 618,181.

This invention relates to electric switches of the oil break type suchas are employed in controlling high potential circuits and has referenceparticularly to the manner of supl porting one of the contact members.

In the use of oil switches such as that shown for example in the patentto Hewlett and Eveleth, No. 1,093,051, where the stationary contactmember has been made segmental in form with the segments held togetherby springs surrounding the contact member and lying in annular groovesin the outer faces of the segments, diiiculty `has been experienced byreason of the destructive action on the stationary contact member and onthe springs by the arc formed between the contacts. It has been foundthat under heavy short circuit conditions the upper portion of a segmentwould be burned away to the first groove with the result that theremaining top portion of the segment would fall into the center bore andat the next closing movement of the switch it would be forced downthrough the bore and destro the contact. It has also been found that t epressure of the hot gases formed at the arc would spread apart thesegments forming the stationary 'contact member and in escaping bel0tween segments eventually burn up the upper spring. It is an object ofthe present invention therefore to provide a construetion whereby thesedifficulties are overcome. Other objects relating to details ofconstruction and arrangement of parts will appear from t-he followingdescription, reference being had to the accompanying drawing forming apart hereof in which:

Figure l is a longitudinal sectional view of the oil pot and partscarried thereby of an oil switch illustrating the invention;

Fig. 2 is an enlarged fragmentary view of the lower portion of Fig. 1;and

Fig. 3 is a transverse sectional view taken on the line 3-3 of Fig. 1. Q

Referring now to the drawing, 1 represents the oil pot or vessel whichis preferably a closed cylinder having an insulation lining 2 andsupported by a member 8 which may be carried in the usual manner b aninsulator, not shown. The cylinder is closed at the top by a cap 4through which extends an insulator 5 and slidably mounted in thisinsulator is a movable contact rod 6. A

baa 7 is provided within the lining 2 of;

the pot and beneath the level of the oil 84 Resting on supports 9 is apartition l0 which is above the level of the oil. A contact holder 1lcarried by the lower portion of the oil pot eneloses the stationarycontact member 12 which, as is usual with switches of this type, istubular with the opening flared at the upper end and is made up of anumber of segments electrically connected wit-h the surrounding holderby means of flexible connectors 13. For holding the segments togetherand in proper position, two so-called garter springs 14 are employed,each of which comprises a helical spring bent around the group ofsegments forming the Contact member and lying in an annular grooveformed on the exterior faces of the segments. The uppermost spring, it 1will be noticed, is spaced a considerable distance, relatively, from theto of the stationary Contact member and ot er means, now to bedescribed,are employed for resiliently pressing against the upper portions of thesegments.

At a point preferably mid-way between the side faces of each se ent, thecontact holder 11 is provided wit a threaded opening into which isscrewed a hollow plug' l5 containing a helical spring 16 to the outerend of which a button 17 is attached. This button is preferably made ofinsulating material to prevent current passing throu h the spring. Whenthe plu is in place t e spring is compressed to ho d the button in firmbut yielding contact with the corresponding segment. f

With this construction the entire up er portion of the stationarycontact mem er may be burned away, yet, since there is no groovein thatvicinity there is no danger of the u per portion of a segment breakingoff and alling into the bore. Furthermore, with the springs 16 andbuttons 17 located at points intermediate the openin s between segmentsthere is no danger of t eir being burned away by the discharge of hotgases unless of courseV the entire upper portion of a segment is burnedoff.

While I have described only one'embodiment of my invention, I do notwish to be limited to the particular form shown and described as it willbe apparent that many modifications therein may be made withoutdelparting om the scope of my invention as set forth in the appendedclaim.

t What I claim as new and desire to secure by Letters Patent of theUnited States, is:

A n electric switch of the liquid break type comprising a vessel forcontaining insulating liquid, a contact holder therein, a movableContact rod, a cooperating tubular contact relatively long com ared toits diameter mounted in sald hol er and having a flared opening at oneend adaptedI to receive the 10 contact rod, said tubular Acontact beingspaced from said holder ermitting lateral and angular movement t ereofin the holder and being formed of a plurality of relatively movablesegments, exible conductors con- 15 meeting the segments with. theholder, resilient means en a 'n the se ents at points nearer to thegedgoppositeg'ntihe flared end of the tubular contact than to the flaredend, and means yieldingly holding the tubular Contact centrally in theholder comprising a. separate radially. acting spring for each segmentarranged between the segment and the holder and nearer to the iared endportion thereof than to the other end land engaging the segmentintermediate its side faces so that said springs are shielded from* arcgases ejected from between the segments. In witness whereof, I havehereunto set my hand this 9th day of February, 1923.

Y I JOHN D. HHJLIARD.

